Conventional tennis rackets are provided with a bow strung with main strings and cross strings to form the head, which is connected at its inner end shoulder portion to the throat of a shaft, sometimes reinforced at the pallet and provided with a grip at its butt end opposite the head. Whether the shaft is provided as a single unitary member or by several members such as in the U.S. Pat. No. 2,085,960 to Donisthorpe, 1936, the same basic geometry is involved wherein the shaft assembly extends between the inner end of the head in a cantilevered manner to the grip. Such a construction has the weakness that it will bend in the manner of a cantilevered beam to change the angle of the racket head according to the force and positioning of the ball upon the strings.
There are many characteristics used to describe rackets, and one of these characteristics is the flexibility or stiffness of the racket. With increased flexibility, increased power may be obtained, but with a loss of control. High speed photography has shown that rackets of the prior art flex greatly, particularly when the ball is hit near the top of the head. In trying to hit the ball as high as possible on the serve, many players tend to hit the ball near the top of the head, and many players hit the ball in excess of 100 miles per hour. The characteristics for such a shot vary greatly from that of a baseline shot hit at low speed and in the center of the racket or towards the grip. The flexibility of the shaft will to a great extent determine which of these two shots will be hit better at the expense of the other, as an example of the role that flexibility plays in a racket.